A147608 Squares which are concatenation of two positive squares with possible intervening zeros.

49, 169, 361, 1225, 1444, 1681, 3249, 4225, 4900, 9025, 15625, 16900, 36100, 42025, 49729, 64009, 81225, 93025, 105625, 122500, 144400, 168100, 225625, 237169, 256036, 324900, 422500, 490000, 519841, 576081, 819025, 902500, 950625, 970225

Offset: 1

Author

Zak Seidov, Nov 08 2008

Keywords

• nonn
• base

Comments

A145848 is a subsequence.

Examples

			324 = 18^2, 9 = 3^2, 3249 = 324:9 = 57^2.
9 = 3^2, 25 = 5^2, 9025 = 9:0:25 = 95^2 (intervening zero).
		

Links

• David W. Wilson, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A039686 (variant with no intervening zeros).

Cf. A145848 (squares with an even number of digits, where the first half is a square and the second half is a nonzero square).

Programs

Mathematica

s={}; Do[n2=n*n; id=IntegerDigits[n2]; Le=Length[id]; Do[If[IntegerQ/@Sqrt[FromDigits/@{Take[id,k], Drop[id,k]}] == {True,True}, If[FromDigits@Drop[id,k]>0, Print[n2]; AppendTo[s,n2]; Break[]]], {k,1,Le-1}], {n,4,10^4}]

Extensions

Edited by Charles R Greathouse IV, Apr 24 2010

Definition corrected by David W. Wilson, Nov 22 2012